How to remediate – Cheops-ng Cleartext Authentication Information Disclosure

1. Introduction

The Cheops-ng Cleartext Authentication Information Disclosure vulnerability allows unencrypted passwords to be transmitted when connecting to a Cheops-ng agent configured for plain text connections. This poses a risk of credential theft and network compromise, as attackers can intercept sensitive information. Systems running the Cheops-ng agent with unencrypted communication enabled are affected. A successful exploit could lead to data confidentiality loss, potential integrity compromises through network mapping, and availability impacts due to brute force attacks.

2. Technical Explanation

The vulnerability occurs because the Cheops-ng agent allows connections without SSL/TLS encryption by default. An attacker can connect to a vulnerable agent using valid credentials and intercept the cleartext password during transmission. This enables network mapping, port scanning, and potentially brute-force login attempts against the host system.

• Root cause: The Cheops-ng agent does not enforce SSL/TLS encryption for connections by default.
• Exploit mechanism: An attacker connects to the agent using a tool like netcat or telnet, captures the cleartext password during authentication, and uses it to map the network or attempt brute force attacks. For example, connecting with `telnet ` will transmit credentials in plain text.
• Scope: Cheops-ng agents running on any platform where unencrypted connections are permitted.

3. Detection and Assessment

To confirm vulnerability, check the agent’s configuration for SSL/TLS settings. A thorough assessment involves monitoring network traffic for cleartext password transmissions.

• Quick checks: Check the Cheops-ng configuration file (location varies by installation) for parameters related to SSL/TLS. Look for options like `ssl_enabled` or similar, and verify they are set to ‘yes’ or equivalent.
• Scanning: Nessus plugin ID 16478 can identify this vulnerability as an example.
• Logs and evidence: Examine Cheops-ng agent logs for authentication attempts without SSL/TLS encryption. Log files may be located in `/var/log/cheops-ng` or a similar directory, depending on the installation.

# Example command placeholder:
grep -i "ssl_enabled" /etc/cheops-ng/cheops-ng.conf

4. Solution / Remediation Steps

Secure Cheops-ng by configuring it to use SSL or block external access if SSL is not feasible.

4.1 Preparation

• Ensure you have valid credentials to access and modify the Cheops-ng configuration. A roll back plan is to restore the backed-up configuration file.
• A change window may be needed depending on your environment. Approval from a system administrator might be required.

4.2 Implementation

1. Step 1: Edit the Cheops-ng configuration file (e.g., `/etc/cheops-ng/cheops-ng.conf`).
2. Step 2: Enable SSL/TLS encryption by setting `ssl_enabled = yes`.
3. Step 3: Specify the path to your SSL certificate and key files using parameters like `ssl_cert` and `ssl_key`.
4. Step 4: Restart the Cheops-ng service.

4.3 Config or Code Example

Before

# /etc/cheops-ng/cheops-ng.conf
ssl_enabled = no

After

# /etc/cheops-ng/cheops-ng.conf
ssl_enabled = yes
ssl_cert = /path/to/your/certificate.pem
ssl_key = /path/to/your/private.key

4.4 Security Practices Relevant to This Vulnerability

Practices that directly address this vulnerability type include least privilege and secure defaults. Least privilege limits the impact of compromised credentials. Secure defaults ensure encryption is enabled by default, reducing configuration errors.

• Practice 1: Implement least privilege for Cheops-ng agent accounts to reduce potential damage from compromised credentials.
• Practice 2: Enforce secure defaults in your configurations to minimize the risk of misconfiguration and exposure of sensitive data.

4.5 Automation (Optional)

# Example Ansible snippet:
- name: Enable SSL for Cheops-ng
  lineinfile:
    path: /etc/cheops-ng/cheops-ng.conf
    regexp: '^ssl_enabled = no'
    line: 'ssl_enabled = yes'
  notify: Restart Cheops-ng
handlers:
  - name: Restart Cheops-ng
    service:
      name: cheops-ng
      state: restarted

5. Verification / Validation

Confirm the fix by checking the agent’s configuration and verifying SSL/TLS encryption is active during connections.

• Post-fix check: Run `grep -i “ssl_enabled” /etc/cheops-ng/cheops-ng.conf` and confirm the output shows `ssl_enabled = yes`.
• Re-test: Attempt to connect to the agent using a tool like netcat or telnet, and verify that the connection is encrypted (e.g., by observing SSL handshake messages).
• Monitoring: Monitor Cheops-ng logs for any errors related to SSL/TLS configuration or certificate validation.

# Post-fix command and expected output
grep -i "ssl_enabled" /etc/cheops-ng/cheops-ng.conf
# Expected Output: ssl_enabled = yes

6. Preventive Measures and Monitoring

Update security baselines to include SSL/TLS encryption for Cheops-ng agents. Implement checks in CI/CD pipelines to prevent unencrypted configurations from being deployed.

• Baselines: Update your security baseline or policy to require SSL/TLS encryption for all Cheops-ng agent deployments.
• Asset and patch process: Review Cheops-ng configurations regularly (e.g., quarterly) as part of your asset management and patch review cycle.

7. Risks, Side Effects, and Roll Back

Enabling SSL/TLS may require certificate management and could introduce compatibility issues with older clients. To roll back, restore the backed-up Cheops-ng configuration file.

• Risk or side effect 1: Certificate expiration can disrupt monitoring. Implement certificate renewal processes to mitigate this risk.
• Roll back:
  1. Stop the Cheops-ng service.
  2. Restore the backed-up configuration file.
  3. Restart the Cheops-ng service.

8. References and Resources